High-frequency stimulation of hippocampal Schaffer collaterals produces a long-lasting enhancement of synaptic transmission at CA3-CA1 synapses. Induction of this phenomenon requires calcium entry through which channel?

• A Voltage-gated sodium channel
• B AMPA receptor channel
• C NMDA receptor channel ✓
• D GABA-A receptor channel

Explanation

Long-term potentiation at CA3-CA1 synapses is NMDA receptor dependent. Strong presynaptic input depolarizes the postsynaptic membrane enough to relieve the magnesium block of the NMDA channel, allowing calcium influx that triggers downstream kinases and sustained synaptic strengthening. AMPA receptors mediate the baseline excitatory transmission and their increased number maintains LTP but does not induce it, and GABA-A channels are inhibitory.

Reference: Kandel, Principles of Neural Science, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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